Major modifications and additions to the previous proposal are highlighted by using shading. This study is designed to provide a population-based perspective on the needs and unmet needs for care among severely mentally ill individuals on Maryland Medicaid. Needs are classified into self care (ADL), community living (IADL), treatment related, productive activities, friends and social networks, and housing. Factors related to needs and unmet needs will be identified through community interviews of 1000 individuals meeting classification and eligibility criteria. The interviews will provide validating information for a claims-based classification of severe and persistent mental illness. In addition, information on psychiatric history and current status, living arrangements, relationships with family and friends, recent arrests, income support, usual source of care, and pattern of treatment (e.g., continuity of visits, medications) will be collected. These characteristics are expected to be predictive of unmet needs for care. Outcome measures will be obtained, including the Quality of Life index, Medical Outcomes health status measure, post-interview hospitalizations and total cost of care to Medicaid. The impact of unmet needs on quality of life, rehospitalization, and Medicaid costs will be assessed. The findings from this study will be used to identify patterns of treatment associated with fewer unmet needs and better health status outcomes. The methods being tested will be useful to all Medicaid programs in identifying the severely mentally ill and in evaluating the overall effectiveness of care provided in each state.